Buttermilk in fish batter?

[ParadiseLaundry]

I have some buttermilk (leftover from making butter from double cream).

I'm planning on battering some fish tonight, does anyone know if I can use the buttermilk instead of normal milk in the batter?

It's actually my first time making battered fish to really thinking I should just be sticking to the recipe

I've used it with chicken, but don't know about fish.
It can be frozen.

Thanks @Georgyporky.

I chickened out and just did a beer batter in the end but it was really nice for my first attempt!

I think I'm going to use the buttermilk for pancakes for the kids tomorrow.